Information processing apparatus, information processing method, and program

Abstract

There is provided an information processing apparatus including a difference applying unit that obtains, according to difference feature information indicating a difference between first feature information characterizing an action of a target user and second feature information characterizing another action performed by the target user after the foregoing action is performed and third feature information characterizing an action newly performed by the target user, fourth feature information; and a target extracting unit that extracts information based on the fourth feature information.

What is claimed is: 
     
         1 . An information processing apparatus comprising:
 a difference applying unit that obtains, according to difference feature information indicating a difference between first feature information characterizing an action of a target user and second feature information characterizing another action performed by the target user after the foregoing action is performed and third feature information characterizing an action newly performed by the target user, fourth feature information; and   a target extracting unit that extracts information based on the fourth feature information.   
     
     
         2 . The information processing apparatus according to  claim 1 ,
 wherein the first feature information is one or a plurality of pieces of content selected by the target user, and   the second feature information is content selected by the target user after the target user selects one or the plurality of pieces of content.   
     
     
         3 . The information processing apparatus according to  claim 1 , wherein the difference applying unit obtains the fourth feature information by causing the difference feature information to affect the third feature information. 
     
     
         4 . The information processing apparatus according to  claim 2 ,
 wherein the first feature information is expressed by a first feature vector,   the second feature information is expressed by a second feature vector,   the difference feature information is expressed by a difference feature vector indicating a difference between the first feature vector and the second feature vector in a feature amount space,   the third feature information is expressed by a third feature vector, and   the difference applying unit obtains, as the fourth feature information, a fourth feature vector by combining the third feature vector and the difference feature vector.   
     
     
         5 . The information processing apparatus according to  claim 4 ,
 wherein the first feature vector is obtained based on a first word vector constituted by a characteristic word group extracted from one or a plurality of pieces of content selected by the target user, and   the second feature vector is obtained based on a second word vector constituted by a characteristic word group extracted from content selected by the target user after the one or the plurality of pieces of content are selected.   
     
     
         6 . The information processing apparatus according to  claim 5 ,
 wherein the first feature vector is obtained by performing dimensional compression on the first word vector constituted by the characteristic word group extracted from the one or the plurality of pieces of content selected by the target user, and   the second feature vector is obtained by mapping, to a feature amount space regulating the first feature vector, the second word vector constituted by the characteristic word group extracted from the content selected by the target user after the one or the plurality of pieces of content are selected.   
     
     
         7 . The information processing apparatus according to  claim 5 ,
 wherein each word constituting the first word vector is set with a weight value according to the degree of significance of the word, and the weight value is considered when the first feature vector is obtained, and   each word constituting the second word vector is set with a weight value according to the degree of significance of the word, and the weight value is considered when the second feature vector is obtained.   
     
     
         8 . The information processing apparatus according to  claim 3 , wherein the difference applying unit obtains the fourth feature information by imparting a predetermined weight to the difference feature information and then causing the difference feature information to affect the third feature information. 
     
     
         9 . The information processing apparatus according to  claim 1 ,
 wherein the first feature information is a first word vector constituted by a characteristic word group extracted from one or a plurality of pieces of content selected by the target user,   the second feature information is a second word vector constituted by a characteristic word group extracted from pieces of content selected by the target user after the one or the plurality of pieces of content are selected, and   the difference feature information is constituted by a disappearing word vector constituted by a word group that is included in the first word vector but not included in the second word vector and an appearing word vector constituted by a word group that is included in the second word vector but not included in the first word vector.   
     
     
         10 . The information processing apparatus according to  claim 9 ,
 wherein the third feature information is a third word vector constituted by a characteristic word group extracted from pieces of content newly selected by the target user, and   the difference applying unit deletes a word included in the disappearing word vector from the third word vector when the word included in the disappearing word vector is included in the third word vector, and obtains the fourth feature information by adding a word included in the appearing word vector to the third word vector when there is a word that is included in the appearing word vector but not in the third word vector.   
     
     
         11 . The information processing apparatus according to  claim 4 , further comprising:
 a difference mapping unit that maps the difference feature vector obtained in a first feature amount space to a second feature amount space using mapping information that causes points within both feature amount spaces to be associated with each other over the first and the second feature amount spaces that belong to different categories,   wherein the difference applying unit obtains the fourth feature vector by combining the third feature vector characterizing pieces of content newly selected by the target user in the category to which the second feature amount space belongs and the difference feature vector mapped to the second feature amount space.   
     
     
         12 . The information processing apparatus according to  claim 1 , wherein the difference applying unit selects feature information having a feature close to that of the third feature information from a plurality of pieces of feature information characterizing an action of a user, and then obtains the fourth feature information using difference feature information corresponding to the selected feature information. 
     
     
         13 . The information processing apparatus according to  claim 1 , wherein the difference applying unit selects a cluster having a feature close to that of the third feature information from a plurality of clusters obtained by clustering a plurality of pieces of feature information characterizing an action of a user, and then obtains the fourth feature information using difference feature information corresponding to feature information representing the selected cluster. 
     
     
         14 . The information processing apparatus according to  claim 1 , further comprising:
 an information providing unit that provides a user with information,   wherein the difference applying unit selects feature information having a feature close to the third feature information from a plurality of pieces of feature information characterizing an action of the user,   the information providing unit provides the user with difference feature information corresponding to the feature information that the difference applying unit selects so as to promote selection of the difference feature information, and   the difference applying unit obtains the fourth feature information using the difference feature information selected by the user.   
     
     
         15 . The information processing apparatus according to  claim 1 , further comprising:
 an information providing unit that provides a user with information,   wherein the difference applying unit selects a cluster having a feature close to that of the third feature information from a plurality of clusters obtained by clustering a plurality of pieces of feature information characterizing an action of the user,   the information providing unit provides the user with difference feature information corresponding to feature information representing a cluster that the difference applying unit selects so as to promote selection of the difference feature information, and   the difference applying unit obtains the fourth feature information using the difference feature information selected by the user.   
     
     
         16 . An information processing method comprising:
 obtaining, according to difference feature information indicating a difference between first feature information characterizing an action of a target user and second feature information characterizing another action performed by the target user after the foregoing action is performed and third feature information characterizing an action newly performed by the target user, fourth feature information; and   extracting information based on the fourth feature information.   
     
     
         17 . A program that causes a computer to realize:
 a difference applying function for obtaining, according to difference feature information indicating a difference between first feature information characterizing an action of a target user and second feature information characterizing another action performed by the target user after the foregoing action is performed and third feature information characterizing an action newly performed by the target user, fourth feature information; and   a target extraction function for extracting information based on the fourth feature information.